Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already establish readOnlyHint=true and openWorldHint=true, so safety and scope are covered. The description adds useful behavioral context by disclosing that the tool returns category tabs containing `cat_id`s and by explaining the intended follow-up use of those IDs.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two short sentences, front-loaded with the core purpose and followed by the routing advice. Every sentence contributes useful information with no wasted text.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a zero-parameter read-only listing tool with an output schema and read-only annotations, the description is complete. It identifies what is listed, the key returned field, and the appropriate follow-up tools.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool takes zero parameters, so there are no parameter semantics to explain. The baseline for a parameterless tool is 4; the description appropriately focuses on the resource and returned identifiers instead.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource: 'List SHEIN brand-channel category tabs with `cat_id`s.' It distinguishes this from siblings by naming `shein_category_goods` for cat_id lookups and `shein_products_search` for brand/name searches.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives clear downstream usage: use the returned `cat_id` with `shein_category_goods`, or use `shein_products_search` for brand/name searches. However, it does not explicitly state when to choose this tool over related siblings like `shein_categories` or `shein_category_nav`.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.